Pressure sensors of the type mentioned at the beginning have also been used in recent times as, e.g., fingerprint sensors. Each of the multiplicity of piezoelectric converter elements is essentially rod-shaped and arranged at a distance from the others and parallel to them. The converter elements are embedded in an insulating material, whereby the free ends of the converter elements are electrically contact-connected. The contact-connection in this association is, as a rule, effected in the manner that each converter element can be separately electrically polled, so that there results a resolution by the corresponding pressure sensor of the exertion of pressure or force that is on an order of magnitude of 500 or more dpi (dots per inch).
The corresponding piezoelectric converter elements thereby generate a surface charge as a result of the corresponding piezoelectric effect, whereby there is essentially a linear relationship between the charge quantity and the deformation of the converter element.
Although such a known pressure sensor is well-suited for use as a fingerprint sensor, it shows, however, low resistivity to high pressures or a stability that is inadequate over the service life to allow use in highly precise mechanical applications with high pressures and over a long time. Were such a pressure sensor to be used, for example, in a bearing that is exactly guided with a high bias pressure, its shrinking would serve to cancel out the bias forces up to the point of absolute, free mobility of the mechanical components, so that this known sensor cannot be used at all for such a purpose.